The frogs are one of many species ,which has not due attention.Yet,it plays(played) a key
role in the human history.
Until mid of nineteenth century(as late as 1950s and 60s),frogs are used for detect pregnancy of human species. The African crab frog was exploited by us for this purpose. Some frog species do develop eggs in their stomach.Now scientists are studying how the eggs are protected by the digestive system(esp from Hydrochloric acid) .This would help us in finding a cure for stomach ulcers. Some frog species are delicacies in China and some chinese medicine use frogs to smoothen our skins.
India being primarily a monsoon dependent land for its survival(and prosperity),A croaking frog indicates the arrival of monsoon and considered as a good omen.Male frogs croaks during rainy season to get attention from female for the mating purpose(photo : Glandular Bush Frog). Hence,a decline of frogs population is a first indicator of imbalance in the environment.
In Rigveda,Frog hymns praise and worship frogs to bring prosperity.One of the hymn says
He(frog) that lows like a cow has given,
he that bleats like a goat has given,
the speckled one,the greenish yellow one has
given prosperity.The frogs have prolonged our life,providing us with hundreds of cows
Interestingly,these frog hymns are used as support claim for Migration of Vedic people from Iran – Avesta similar to Rigveda do not have frog hymns,because no monsoons in Iran(Nevertheless,Romila Thapar and few other Historians don't subscribe to this invasion theory)